• 제목/요약/키워드: variance structure

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Beamforming을 이용한 TPMS 간섭제거 (TPMS Interference Suppression Based on Beamforming)

  • 황석승;김성민;박철
    • 한국전자통신학회논문지
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    • 제6권2호
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    • pp.180-185
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    • 2011
  • TPMS(Tire Pressure Monitoring System)는 차량의 주행 또는 정차시 타이어의 압력 또는 온도 등에 따른 이상 유무를 측정하여 수신기의 표시장치에 해당 상황을 나타내주도록 설계된 안전 보조 시스템이다. TPMS의 센서부에서 측정한 데이터를 자동차 내부의 신호처리부로 무선통신을 이용하여 전송하는데, 통신 시에 다양한 간섭으로 인한 통신 장애가 발생할 수 있다. 대표적인 TPMS 간섭으로 아마추어 무선국, 컨테이너 관리용 RFID(Radio-Frequency IDentification), RKE(Remote Keyless Entry) 신호 등을 들 수 있다. 이러한 다양하면서도 높은 전력을 가지는 간섭들을 제거하기 위하여 본 논문에서는 빔형성(Beamforming) 기술을 고려한다. 이에 따른 데이터 구조 및 빔형성기에 알맞는 차량내부의 안테나 배치 등을 제안한다. 컴퓨터 시뮬레이션을 통하여 본 논문에서 제안된 기술의 간섭제거 성능을 확인 할 것이다.

CHAINED COMPUTATIONS USING AN UNSTEADY 3D APPROACH FOR THE DETERMINATION OF THERMAL FATIGUE IN A T-JUNCTION OF A PWR NUCLEAR PLANT

  • Pasutto, Thomas;PENiguel, Christophe;Sakiz, Marc
    • Nuclear Engineering and Technology
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    • 제38권2호
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    • pp.147-154
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    • 2006
  • Thermal fatigue of the coolant circuits of PWR plants is a major issue for nuclear safety. The problem is especially accute in mixing zones, like T-junctions, where large differences in water temperature between the two inlets and high levels of turbulence can lead to large temperature fluctuations at the wall. Until recently, studies on the matter had been tackled at EDF using steady methods: the fluid flow was solved with a CFD code using an averaged turbulence model, which led to the knowledge of the mean temperature and temperature variance at each point of the wall. But, being based on averaged quantities, this method could not reproduce the unsteady and 3D effects of the problem, like phase lag in temperature oscillations between two points, which can generate important stresses. Benefiting from advances in computer power and turbulence modelling, a new methodology is now applied, that allows to take these effects into account. The CFD tool Code_Saturne, developped at EDF, is used to solve the fluid flow using an unsteady L.E.S. approach. It is coupled with the thermal code Syrthes, which propagates the temperature fluctuations into the wall thickness. The instantaneous temperature field inside the wall can then be extracted and used for structure mechanics computations (mainly with EDF thermomechanics tool Code_Aster). The purpose of this paper is to present the application of this methodology to the simulation of a straight T-junction mock-up, similar to the Residual Heat Remover (RHR) junction found in N4 type PWR nuclear plants, and designed to study thermal striping and cracks propagation. The results are generally in good agreement with the measurements; yet, in certain areas of the flow, progress is still needed in L.E.S. modelling and in the treatment of instantaneous heat transfer at the wall.

피복구성학적 인체계측과 집낙구조분석 ( I ) (Anthropometry for clothing construction and cluster analysis ( I ))

  • 김구자
    • 한국의류학회지
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    • 제10권3호
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    • pp.37-48
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    • 1986
  • The purpose of this study was to analyze 'the natural groupings' of subjects in order to classify highly similar somatotype for clothing construction. The sample for the study was drawn randomly out of senior high school boys in Seoul urban area. The sample size was 425 boys between age 16 and 18. Cluster analysis was more concerned with finding the hierarchical structure of subjects by three dimensional distance of stature. bust girth and sleeve length. The groups forming a partition can be subdivided into 5 and 6 sets by the hierarchical tree of the given subjects. Ward's Minimum Variance Method was applied after extraction of distance matrix by the Standardized Euclidean Distance. All of the above data was analyzed by the computer installed at Korea Advanced Institute of Science and Technology. The major findings, take for instance, of 16 age group can be summarized as follows. The results of cluster analysis of this study: 1. Cluster 1 (32 persons means $18.29\%$ of the total) is characterized with smaller bust girth than that of cluster 5, but stature and sleeve length of the cluster 1 are the largest group. 2. Cluster 2 (18 Persons means $10.29\%$ of the total) is characterized with the group of the smallest stature and sleeve length, but bust girth larger than that of cluster 3. 3. Cluster 3(35persons means $20\%$ of the total) is classified with the smallest group of all the stature, bust girth and sleeve length. 4. Cluster 4(60 persons means $34.29\%$ of the total) is grouped with the same value of sleeve length with the mean value of 16 age group, but the stature and bust girth is smaller than the mean value of this age group. 5. Cluster 5(30 persons means $17.14\%$ of the total) is characterized with smaller stature than that of cluster 1, and with larger bust girth than that of cluster 1, but with the same value of the sleeve length with the mean value of the 16 age group.

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위계적 선형모형을 이용한 강의평가 결정요인 분석 (Determinants of student course evaluation using hierarchical linear model)

  • 조장식
    • Journal of the Korean Data and Information Science Society
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    • 제24권6호
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    • pp.1285-1296
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    • 2013
  • 강의평가 결과에 영향을 미치는 특성변수로는 교과목 수준의 다양한 강좌특성 변수들과 수강생 수준의 다양한 인적특성 변수들이 있다. 특정 수강생은 다수의 교과목을 이수하기 때문에 다수의 교과목들은 동일한 수강생 안에 속하게 됨으로써 공유되는 특성이 있게 된다. 즉 강의평가 결과는 교과목 수준의 강좌특성 (1-수준)과 수강생 수준의 인적특성 (2-수준)에 의해 영향을 받는 다층구조 (multilevel)를 가지게 되며, 위계적 자료 특성을 가지는 복수의 분석단위의 구조가 된다. 따라서 전통적인 회귀분석에서와 같이 개별 교과목들이 독립이라는 가정을 할 수 없게 된다. 본 논문에서는 강의평가결과에 영향을 미치는 다층구조의 특성을 가진 변수들의 영향력을 보다 타당하게 분석하기 위한 방법으로 위계선형모형 (HLM; hierarchical linear model)을 이용하였다. 분석결과는 다음과 같다. 먼저 교과목 수준의 특성변수들 중에 강좌규모, 개설학년, 담당교수의 전임여부, 해당 교과목의 총 평균평점, 원어강좌 여부가 통계적으로 유의하게 강의평가 결과에 영향을 미친 것으로 나타났다. 또한 수강생 수준의 인적특성 변수들 중에는 성별, 학과계열, 대입당시 전형방법, 평균평점 등이 유의하게 강의평가 결과에 영향을 미친 것으로 나타났다.

Effects of Acarbose Addition on Ruminal Bacterial Microbiota, Lipopolysaccharide Levels and Fermentation Characteristics In vitro

  • Yin, Yu-Yang;Liu, Yu-Jie;Zhu, Wei-Yun;Mao, Sheng-Yong
    • Asian-Australasian Journal of Animal Sciences
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    • 제27권12호
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    • pp.1726-1735
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    • 2014
  • This study investigated the effects of acarbose addition on changes in ruminal fermentation characteristics and the composition of the ruminal bacterial community in vitro using batch cultures. Rumen fluid was collected from the rumens of three cannulated Holstein cattle fed forage ad libitum that was supplemented with 6 kg of concentrate. The batch cultures consisted of 8 mL of strained rumen fluid in 40 mL of an anaerobic buffer containing 0.49 g of corn grain, 0.21 g of soybean meal, 0.15 g of alfalfa and 0.15g of Leymus chinensis. Acarbose was added to incubation bottles to achieve final concentrations of 0.1, 0.2, and 0.4 mg/mL. After incubation for 24 h, the addition of acarbose linearly decreased (p<0.05) the total gas production and the concentrations of acetate, propionate, butyrate, total volatile fatty acids, lactate and lipopolysaccharide (LPS). It also linearly increased (p<0.05) the ratio of acetate to propionate, the concentrations of isovalerate, valerate and ammonia-nitrogen and the pH value compared with the control. Pyrosequencing of the 16S rRNA gene showed that the addition of acarbose decreased (p<0.05) the proportion of Firmicutes and Proteobacteria and increased (p<0.05) the percentage of Bacteroidetes, Fibrobacteres, and Synergistetes compared with the control. A principal coordinates analysis plot based on unweighted UniFrac values and molecular variance analysis revealed that the structure of the ruminal bacterial communities in the control was different to that of the ruminal microbiota in the acarbose group. In conclusion, acarbose addition can affect the composition of the ruminal microbial community and may be potentially useful for preventing the occurrence of ruminal acidosis and the accumulation of LPS in the rumen.

한국어판 '암 환자가 인식하는 간호의 질 측정도구'의 타당도와 신뢰도 (Validity and Reliability Test of the Korean Version of the Oncology Patients' Perception of the Quality of Nursing Care Scale)

  • 강지영;강혜영;김나년;이미정;김유진;김주현;여수정;서윤예;서은영
    • 성인간호학회지
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    • 제28권2호
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    • pp.191-201
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    • 2016
  • Purpose: The purpose of this methodological study was to examine the validity and reliability of a translated Korean version of The Oncology Patients' Perception of the Quality of Nursing Care Scale. Methods: The translated scale was pilot tested and then administered to 360 patients with cancer. Exploratory and confirmatory factor analyses were utilized to assess the factor structure. Internal consistency reliability was determined using coefficient ${\alpha}$. Results: Two of the 40 items were deleted with a principal component method of exploratory factor analysis because they did not meet the factor-loading criterion. The 38 items were again analyzed and, four factors were validated (KMO=.96, Bartlett ${\chi}^2=10809.81$, df=780, p<.001). The four factors accounted for 60.9% of the variance. Factor loadings of the scale on the four subscales ranged from .65 to .91. The scale showed reliable internal consistency with a Cronbach's ${\alpha}$, total 38 items (${\alpha}=.96$) in four subscales: individualization (18 items, ${\alpha}=.96$), proficiency (10, .91), responsiveness (7, .90), and coordination (3, .80). Conclusion: The findings of this study demonstrate that the scale has satisfactory construct validity and reliability to measure quality of cancer nursing care from the patient's perspective in Korea.

Association of the Single Nucleotide Polymorphisms in RUNX1, DYRK1A, and KCNJ15 with Blood Related Traits in Pigs

  • Lee, Jae-Bong;Yoo, Chae-Kyoung;Park, Hee-Bok;Cho, In-Cheol;Lim, Hyun-Tae
    • Asian-Australasian Journal of Animal Sciences
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    • 제29권12호
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    • pp.1675-1681
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    • 2016
  • The aim of this study was to detect positional candidate genes located within the support interval (SI) regions based on the results of red blood cell, mean corpuscular volume (MCV), and mean corpuscular hemoglobin quantitative trait locus (QTL) in Sus scrofa chromosome 13, and to verify the correlation between specific single-nucleotide polymorphisms (SNPs) located in the exonic region of the positional candidate gene and the three genetic traits. The flanking markers of the three QTL SI regions are SW38 and S0215. Within the QTL SI regions, 44 genes were located, and runt-related transcription factor 1, dual-specificity tyrosine-(Y)-phosphorylation regulated kinase 1A (DYRK1A), and potassium inwardly-rectifying channel, subfamily J, member 15 KCNJ15-which are reported to be related to the hematological traits and clinical features of Down syndrome-were selected as positional candidate genes. The ten SNPs located in the exonic region of the three genes were detected by next generation sequencing. A total of 1,232 pigs of an $F_2$ resource population between Landrace and Korean native pigs were genotyped. To investigate the effects of the three genes on each genotype, a mixed-effect model which is the considering family structure model was used to evaluate the associations between the SNPs and three genetic traits in the $F_2$ intercross population. Among them, the MCV level was highly significant (nominal $p=9.8{\times}10^{-9}$) in association with the DYRK1A-SNP1 (c.2989 G$F_2$ intercross, our approach has limited power to distinguish one particular positional candidate gene from a QTL region.

다차원적 종교성/영성척도 단축형 한국어판의 타당화 (Validation of the Korean Version of Brief Multidimensional Measure of Religiousness/Spirituality Scale)

  • 윤혜영;김근향
    • 한국융합학회논문지
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    • 제6권5호
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    • pp.257-274
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    • 2015
  • 본 연구는 Fetzer/NIA(1999)에서 개발한 다차원적 종교성/영성 척도-단축형(Brief-Multidimensional Measure of Religiousness/Spirituality Scale; BMMRS)의 신뢰도와 타당도를 평가하기 위해서 실시되었다. 대학생, 대학원생과 종교를 믿는 일반 성인 286명을 대상으로 BMMRS 영적 웰빙척도(Spiritual Well-Being Scale, SWS), 한국판 영성 척도(Korean Sprituality Scale, KSS), 펜실베니아 걱정질문지(Penn State Worry Questionnaire, PSWQ), 불확실성에 대한 인내력 부족 척도(Intolerance of uncertainty Scale, (IUS)를 실시하였다. BMMRS의 요인구조를 주축분해법, 사각 회전으로 분석한 결과, 기존 연구에서 제안되었던 긍정적 영적 경험, 부정적 영적 경험, 용서, 종교활동, 긍정적인 종교지지, 부정적인 종교지지 6요인 구조가 확인되었고 확인적 요인분석 결과 모형 적합도도 만족할 만한 수준이었다. 각 소척도의 내적일관성(.64~.97)과 검사-재검사 신뢰도(.72~.88) 역시 적절하였다. 이 결과는 한국판 BMMRS가 적절한 심리 측정적 지표를 나타내고 있음을 보여주고 있으며, 이에 향후 영성과 종교성 및 정신건강의 관련성 연구에 사용될 수 있음을 시사하였다.

트레드밀을 이용한 보행간 Variability 분석에 관한 연구 (A Study on Stride-to-stride Variability by Treadmill Walking)

  • 최진승;강동원;탁계래
    • 한국운동역학회지
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    • 제17권4호
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    • pp.1-8
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    • 2007
  • The purpose of this study was to investigate the difference in the stride-to-stride variability between two treadmill conditions; traditional treadmill and special treadmill whose speed can be adjusted automatically by subject's walking speed. Eight male subjects (25.1 years, 172.7 cm, 66.6 kg) were participated in treadmill walking experiment. First, preferred walking speed (PWS) of each subject was determined. Second, each subject performed walking experiment with fixed PWS condition and with free PWS condition for 10 minutes. 3D motion capture system (Motion analysis Corp., USA) with 6 cameras was used to collect motion data with sampling frequency of 120Hz. Temporal and spatial variables for stride-to-stride variability were calculated. Coefficient of variance (CV) which quantifies the amount of variability and Detrended Fluctuation Analysis (DFA) which explains the structure (self-similarity) of the variability were used for analysis. Results showed that the amount of variability during free PWS condition was greater than that of fixed PWS condition. DFA results showed that there was a statistical difference between two treadmill conditions for the variables of step length, stance time, and double support time. From these results, it is possible that traditional treadmill study might give incorrect conclusion about gait variability study. Further study is necessary to clarify these matters by considering the number of subjects, experimental time, and gait variables for the study of stride-to-stride variability.

The Effect of Plantar Foot Pressure Negotitating Obstacles in the Elderly

  • Seo, Kyo-Chul;Kim, Hyeun-Ae;Kim, Hee-Tak;Kim, Sung-Gyung;Kim, Jin-Sang
    • The Journal of Korean Physical Therapy
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    • 제23권6호
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    • pp.15-22
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    • 2011
  • Purpose: This research investigated falls due to obstacles that occur among elderly people by assessing changes in the values of plantar foot force, peak force, and plantar foot pressure in elderly subjects while they were stepping over obstacles of different heights. Methods: The subjects were 20 elderly people aged 70-80 years; Pressure was measured on flat ground(0 cm), and after installing obstacles of 8 cm and 12 cm using the F-scan system, which is a resistance-type pressure sensor. A one-way analysis of variance was performed to compare pressure on each part of the foot according to various heights after collecting data using the Tekscan program. The least significant difference test was used for the post-hoc analysis, A p-value <0.05 was considered significant. Results: The force value for the toe area (parts 1, and 2) and contact pressure increased significantly with the 12 cm obstacle (p<0.05). The peak force value and the peak contact pressure for part 1 increased significantly with the 12 cm obstacle (p<0.05). Conclusion: Larger changes appeared in the functions and structure of the foot while subjects walked over obstacles of different heights compared to flatland walking. This result suggests that people have safety strategies to prevent falls, and that there is a need for a more realistic approach through practice to overcome obstacles of various heights to prevent falls.